1. Field of The Invention
The invention relates to a recording apparatus for recording an information signal in at least one track on a record carrier, the information signal comprising packets that may occur irregularly as a function of time in the serial datastream of the information signal.
2. Description of The Related Art
The recording of an MPEG encoded information signal on a record carrier, such as a magnetic record carrier, is known from Research Disclosure, October 1994, p. 581, Publication No. 36629. Although the publication discusses the recording of feature mode information on the record carrier, more specifically, by means of a recording apparatus of the helical scan type, it should be noted that the present invention is not restricted to that. The information to be recorded can thus relate to the information that can be reproduced at a nominal transport velocity of the record carrier during reproduction.
The MPEG encoded information signal comprises transport packets that may occur irregularly in the serial datastream of the MPEG transport stream.
The ISO/IEC 13.818 International Standard, Part 1 `Systems`, dated 13 Nov. 1994, contains a description of a transport system for transmitting an MPEG information signal, which may include a data-compressed digital video signal and a corresponding data-compressed digital audio signal, for broadcasting purposes or for transmission via a cable network. The MPEG information signal is in the form of transport packets comprising 188 bytes of information each.
Packets in the MPEG serial data stream comprise, apart from `system information`, one kind of information, that is: either a portion of a video signal, or a portion of an audio signal, or a portion of a data signal. A plurality of video signals and/or a plurality of audio signals and/or a plurality of data signals may be transmitted via the transport packets in the MPEG serial data stream. A packet also comprises information of only one of the video signals, or one of the audio signals, or one of the data signals transmitted via the MPEG serial data stream.
A transmission of such MPEG information signal in the form of a recording on and a reproduction from a record carrier, requires special measures to be taken in order to realize such kind of transmission.
Earlier filed applications U.S. patent application Ser. No. 08/225,193, having a filing date of Apr. 8, 1994, now U.S. Pat. No. 5,579,183 (PHN 14.818), and U.S. patent application Ser. No. 08/253,535, having a filing date of Jun. 3, 1994, now U.S. Pat. No. 5,596,581 (PHA 21.886), describe various of such measures to realize a recording and reproduction of an MPEG information signal.
It can generally be said that the recording of a complete MPEG information signal is not well possible, because of the too high data rate of the MPEG information signal.
One of the video signals and its corresponding audio signal(s) included in the MPEG serial datastream are now selected for recording. As a consequence, generally, transport packets will be selected on an irregular basis as a function of time. In order to preserve the timing relation between the subsequent packets selected, after having recorded and reproduced the packets, the earlier filed documents describe the measure of inserting timing information (or a `time stamp`) in each of the packets recorded. Upon reproduction, the timing relation between the subsequent packets can be regained using the time stamps.